Scientists agree almost universally that dinosaurs were wiped out 65 million years ago, although researchers continue to study the specific causes. The American Museum of Natural History in New York notes that a comet or asteroid strike along with “massive volcanic eruptions and changing sea levels” all may have played a role.

A 36-foot-long Pliosaurus attacks the plesiosaur Cryptoclidus, a marine reptile from the Late Jurassic Period. Also shown: the fish Pachycormus, a shoal of the belemnite Belemnoteuthis, and the ammonite Pectinatites.
Acrylic Painting, 2008.